• Journal of the Korean Society of Radiology
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• v.1 no.2
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• pp.23-30
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• 2007

This paper presents a method of generating 3-dimensional images by preprocessing 2-dimensional abdominal images obtained using CT (computed tomography) and MRI (magnetic resonance imaging) through segmentation, threshold technique, etc. and apply the method to virtual endoscopy. Three-dimensional images were visualized using indirect volume rendering, which can render at high speed using a general-purpose graphic accelerator used in personal computers. The algorithm used in the rendering is Marching Cubes, which has only a small volume of calculation. In addition, we suggested a method of producing 3-dimensional images in VRML (virtual reality modeling language) running on the Web browser without a workstation or an exclusive program. The number of nodes, the number of triangles and the size of a 3-dimensional image file from CT were 85,367, 174,150 and 10,124, respectively, and those from MRI were 34,029, 67,824 and 3,804, respectively.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.681-684
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• 2015

Magnetization is very important in the ferro-magnetic physics and provides useful informations in the application field of magnetic devices. Generally, the only first acquired domain pattern is not helpful to recognize domain pattern. Many images are needed to visualize domain pattern through image processing. These images were obtained a 8-bit digital camera. The operation was the subtraction of pixel values of multi domain imanges from the images with 255 of pixel value, which was obtained in the saturated state of magnetic materials. The magnetic domain images was visualized gradually with increasing the number of subtracion operation. LABVIEW was used as an image processing tool and the optic microscope with a polarizer was used in this experiment.

• Investigative Magnetic Resonance Imaging
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• v.12 no.2
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• pp.131-141
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• 2008

Purpose : To investigate the feasibility and accuracy of Proton Resonance Frequency (PRF) shift based magnetic resonance (MR) temperature mapping utilizing the self-developed center array-sequencing phase unwrapping (PU) method for non-invasive temperature monitoring. Materials and Methods : The computer simulation was done on the PU algorithm for performance evaluation before further application to MR thermometry. The MR experiments were conducted in two approaches namely PU experiment, and temperature mapping experiment based on the PU technique with all the image postprocessing implemented in MATLAB. A 1.5T MR scanner employing a knee coil with $T2^*$ GRE (Gradient Recalled Echo) pulse sequence were used throughout the experiments. Various subjects such as water phantom, orange, and agarose gel phantom were used for the assessment of the self-developed PU algorithm. The MR temperature mapping experiment was initially attempted on the agarose gel phantom only with the application of a custom-made thermoregulating water pump as the heating source. Heat was generated to the phantom via hot water circulation whilst temperature variation was observed with T-type thermocouple. The PU program was implemented on the reconstructed wrapped phase images prior to map the temperature distribution of subjects. As the temperature change is directly proportional to the phase difference map, the absolute temperature could be estimated from the summation of the computed temperature difference with the measured ambient temperature of subjects. Results : The PU technique successfully recovered and removed the phase wrapping artifacts on MR phase images with various subjects by producing a smooth and continuous phase map thus producing a more reliable temperature map. Conclusion : This work presented a rapid, and robust self-developed center array-sequencing PU algorithm feasible for the application of MR temperature mapping according to the PRF phase shift property.

• Journal of the Korea Computer Industry Society
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• v.3 no.12
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• pp.1775-1784
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• 2002

Fingerprint recognition technology is used in many biometrics field accordingly essential feature of fingerprint image and the study is progressing. However development is not perfect in performance of the fingerprint recognition and application of the usual life. In the paper, we study various necessity of preprocessing according to algorithm and circumstances of authentication system in automatic information machine. We prove that system circumstance and optation of fingerprints image effectively is the important factor by using optical fingerprint input device and scanning the fingerprint in ID card. And then we present correct and fast computation method for improving image and feature extraction of fingerprint. Also we study effective algorithm implementation of total system.

• The KIPS Transactions:PartB
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• v.18B no.3
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• pp.109-116
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• 2011

In this paper, we introduce non-touch style interface system technology without any touch style controlling mechanism, which is called as "Air-interface". To develop this system, we used the full reflection principle of infrared (IR) light and then user's hand is separated from the background with the obtained image at every frame. The segmented hand region at every frame is used as input data for an hand-motion recognition module, and the hand-motion recognition module performs a suitable control event that has been mapped into the specified hand-motion through verifying the hand-motion. In this paper, we introduce some developed and suggested methods for image processing and hand-motion recognition. The developed air-touch technology will be very useful for advertizement panel, entertainment presentation system, kiosk system and so many applications.

• Journal of the Korea Convergence Society
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• v.10 no.11
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• pp.111-116
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• 2019

With recent rapid development of computer capabilities, various technologies that can facilitate the interaction between humans and computers are being studied. The paradigm tends to change to NUI using the body such as 3D motion, haptics, and multi-touch with GUI using traditional input devices. Various studies have been conducted on transferring human movements to computers using sensors. In addition to the development of optical sensors that can acquire 3D objects, the range of applications in the industrial, medical, and user interface fields has been expanded. In this paper, I provide a model that can execute other programs through gestures instead of the mouse, which is the default input device, and control Windows based on the lip motion. To propose a model which converges with an Android application and can be controlled by various media and voice instruction functions using voice recognition and buttons through connection with a main client. It is expected that Internet media such as video and music can be controlled not only by a client computer but also by an application at a long distance and that convenient media viewing can be performed through the proposal model.

• The KIPS Transactions:PartB
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• v.10B no.7
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• pp.803-810
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• 2003

In this paper, we describe a fast image mosaic method for constructing a large-scale image with video image captured from cameras that are arranged in radial shape. In the first step, we adopt the phase correlation algorithm to estimate the horizontal and vertical displacement between two adjacent images. Secondly, we calculate the accurate transform matrix among those cameras with Levenberg-Marquardt method. In the last step, those images are stitched into one large scale image in real-time by applying the transform matrix to the texture mapping function of DirectX. The feature of the method is that we do not need to use special hardware devices or write machine-level programs for Implementing a real-time mosaic system since we use conventional graphic APIs (Application Programming Interfaces), DirectX for image synthesis process.

• Information and Communications Magazine
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• v.29 no.12
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• pp.55-61
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• 2012

최근 통신 기술 및 IT기술을 발전이 급속히 이루어지면서 산업 및 사회 전반에 통신을 빼놓고는 일상 생활을 논할 수 없는 환경이 되었다. 특히 수만은 종류의 모바일 단말들이 널리 보급되면서 언제 어디서나 정보를 접근하고 획득할 수 있는 환경이 구축되어 있으며, 실시간 정보를 들을 접할 수 있는 환경이 조성되었다. 특히 통신 관련 장치가 소형화되고 저전력 기술이 적용되면서, 전에는 접할 수 없었던 특정 사물(컴퓨터, 프린터, 가전, 액츄에이터, 동영상 등)에 대한 네트워크적인 접근이 가능하며, 심지어 각종 센서 정보를 원격을 점검할 수 있게 되었다. 이러한 변화는 실 세계의 사물을 응용 단의 하나의 자원으로 활용할 수 있는 환경이 조성되었으며, 특히 웹 기술을 이용해서 자원을 검색하고 접속/제어하려는 작업이 즉, Web of Things(WoT)개발이 이루어지고 있다. 본 논문에서는 WoT에 대한 개념 및 기술적이슈/표준화적 이슈에 대해서 논한다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2015.07a
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• pp.441-443
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• 2015

디지털 홀로그래픽 TV 시스템을 구현하려면 홀로그래픽 정보 획득 장치가 필요한데, 해상도 한계 때문에 홀로그램의 프린지 패턴을 상용 촬상 소자로는 직접 기록할 수 없다. 이를 극복하는 방법으로는 컬러 영상과 거리영상 정보를 얻은 후에 압축을 거쳐 수신 디스플레이단에 전송하고 이 정보로부터 3차원 모델을 형성한 후에 컴퓨터 생성 홀로그램을 생성하고 이를 회절소자를 이용하여 디스플레이하는 방법이 현재로서는 현실적인 방법이 될 것이다. 홀로그래픽 디스플레이에서는 회절소자인 공간광변조기 성능의 한계 때문에 기존 2DTV와 같은 수준의 디스플레이 구현은 매우 어렵다. 기존 공간광변조기는 픽셀피치가 커서 시야각이 매우 좁으나, 픽셀 크기를 작게 하는 동시에 공간광변조기 면적을 크게 하기에는 기술적인 어려움이 많다. 본 논문에서는 홀로그래픽 TV를 구현하는데 있어서 기술적으로 극복하고 고려해야 할 주요 요소에 대하여 분석한다.

• The Journal of the Korea Contents Association
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• v.6 no.1
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• pp.143-150
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• 2006

Recently, the fields such as internet banking and electronic commerce are more and more growing due to the growth of practical use of personal computer and the progress of communication technology, So importance of information security has been increased. In fact, traditional identification systems are inherently insecure because the personal identification information can be forgotten, stolen or lost. In this paper, we propose an identification system that can decide whether the user is registered based on iris information using a mouse. The proposed system is mounted a CCD camera and an illumination device on general type mouse. Then it decides whether the user is registered after the acquired image are processed and analyzed. This system gives a PC user the advantage of low-cost and convenience without necessity preparing high-cost equipment for biometrics when using a identification system.